Hakone volcano, (12 x 8 kms caldera) close to Tokyo, was 'activated' after last years mega quake

'Conclusions
Seismic activity in the Hakone volcano was significantly
activated just after the occurrence of the 2011 off the Pacific
coast of Tohoku Earthquake. The onset of seismicity was
initiated during the Love and Rayleigh waves from the main
shock. The seismic activity persisted for approximately one
month, with more than 1600 events occurring.'

[link to www.terrapub.co.jp]

remember, Tokyo is due a big quake when the Phillipine plate slips under the Asian plate

if a quake hundreds of miles from it did that, what will a quake right next door to it do? A quake that WILL happen.

[link to i43.tinypic.com]

that shows you where Hakone is.

'We would like to note
that seismicity around the northern end of the Tanna Fault
was activated after the main shock, where earthquakes were
previously hardly observed. We installed 21 offline temporary
stations in and around the Hakone caldera prior to the
main shock and we are continuing the observation.'

were they worried? did they know what was coming?

last time this erupted was 3000 years ago.